Butterfly Valve in intake manifold - Rennlist - Porsche Discussion Forums

911 Forum
Sponsored by:

Butterfly Valve in intake manifold

Old 01-14-2019, 04:38 AM
Heater Guy
Thread Starter
Join Date: Feb 2015
Posts: 8
Default Butterfly Valve in intake manifold

My 2008 Cayman 2.4 L track car's intake has a vacuum controlled butterfly valve in the back cross tube of the intake manifold.

Photos attached

What is the purpose of this valve?? It is acuated by an electrically controlled vacuum solenoid. Can someone explain it?

Any reason why I can't remove it and tell the computer to ignore the code?

Heater Guy is offline  
Old 01-14-2019, 01:17 PM
Auto_Werks 3.6
Quit Smokin'
Rennlist Member
Auto_Werks 3.6's Avatar
Join Date: Dec 2003
Location: Columbus, Ohio
Posts: 1,928

So you're posting in the air cooled 911 specific forum, and you may get a more accurate answer if you re post in a cayman specific area. That said; It looks like a resonance flap, that would be used for changing the volume of the intake manifold for different parts of the RPM range. The 964 engine has something very similar. The change in intake volume changes the resonance created within the manifold that is used to increase cylinder filling. If you lock it in one position you will be very sad with the result. You will either lose somewhere near 10% torque in the low end, or take a big whack off the top end power. If you do some searches you can find dyno sheets where 964 owners or shops have locked them out to show the measured effects.
Auto_Werks 3.6 is offline  

Thread Tools
Search this Thread

Contact Us About Us Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: